- #1
Yuqing
- 218
- 0
I was using extra virgin olive oil recently and noticed something peculiar. I had always thought that oils will spread when in contact with water, but the olive oil didn't seem to do so.
When the oil entered the water, they were pinched into spheres which quickly rose to the surface. The thing is when the spherical drops reached the top, they did not break the water surface and enter the water-air interface. Instead, they remained more or less spherical right under the water surface, with perhaps a tiny area exposed to the air at the top. After a bit of a delay, the spherical droplets will then spread into a larger circular lens. Notably, the larger drops tend to do this more readily than the smaller drops. What causes the drops to remain under the water surface without breaking it, surely buoyancy will cause it to rise further. Secondly, what then causes the oil to spread into a lens? I have looked at spreading and entering coefficients for olive oil and water, and both of these are positive indicating that entering and spreading should be favourable opposed to this behavior.
When the oil entered the water, they were pinched into spheres which quickly rose to the surface. The thing is when the spherical drops reached the top, they did not break the water surface and enter the water-air interface. Instead, they remained more or less spherical right under the water surface, with perhaps a tiny area exposed to the air at the top. After a bit of a delay, the spherical droplets will then spread into a larger circular lens. Notably, the larger drops tend to do this more readily than the smaller drops. What causes the drops to remain under the water surface without breaking it, surely buoyancy will cause it to rise further. Secondly, what then causes the oil to spread into a lens? I have looked at spreading and entering coefficients for olive oil and water, and both of these are positive indicating that entering and spreading should be favourable opposed to this behavior.